Polymeric electrolyte and lithium battery employing the same

ABSTRACT

A polymeric electrolyte and a lithium battery lithium employing the same. The polymeric electrolyte includes a cross-linked polyether urethane prepared by reacting a pre-polymer having a polyethylene oxide backbone and terminated with NCO, with a cross-linking agent, organic solvent and lithium salt. Since the polymeric electrolyte is electrochemically stable, a lithium battery having improved reliability and safety can be obtained by employing the polymeric electrolyte.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Korean Patent Application No.00-57340 filed on Sep. 29, 2000 in the Korean Industrial PropertyOffice, the contents of which is incorporated hereinto by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a lithium battery, and moreparticularly, to an electrochemically stable polymeric electrolyte and alithium battery using the same.

[0004] 2. Description of the Related Art

[0005] Lithium secondary batteries generate electricity by lithium ionsmigrating between a cathode and an anode. The lithium secondary batterybatteries have higher energy density per volume and have a highervoltage, than lithium cadmium batteries or nickel hydrogen batteries.Also, the lithium secondary batteries are lightweight compared tolithium cadmium batteries or nickel hydrogen batteries, that is,approximately a half. Thus, the lithium secondary batteries are welladapted for miniaturization and long-time use of electronic appliances.

[0006] As described above, since the lithium secondary batteries havehigher voltage characteristics and a better charging/discharge cyclelife than conventional nickel cadmium batteries or nickel hydrogenbatteries, without causing environmental problems, much attention hasbeen paid thereto as the most promising high-performance batteries.However, it is a critical issue to attain safety due to danger ofexplosion of a lithium secondary battery.

[0007] In order to secure the safety of a lithium secondary battery, itis important to attain the electrochemical stability of a material usedas an electrolyte. In other words, in order to obtain a safe lithiumsecondary battery, it is very important to employ an electrolyte free ofthe danger of being dissolved at 2.75 to 4.3 V.

SUMMARY OF THE INVENTION

[0008] To solve the above problems, it is a first object of the presentinvention to provide a new polymeric electrolyte which iselectrochemically stable.

[0009] It is a second object of the present invention to provide amethod of preparing the polymeric electrolyte.

[0010] It is a third object of the present invention to provide alithium battery having improved safety by employing the polymericelectrolyte.

[0011] It is a fourth object of the present invention to provide amethod of manufacturing the lithium battery.

[0012] Additional objects and advantages of the invention will be setforth in part in the description which follows and, in part, will beobvious from the description, or may be learned by practice of theinvention.

[0013] To achieve the above and other objects of the present invention across-linked polyether urethane polymeric electrolyte prepared byreacting a pre-polymer having a polyethylene oxide backbone andterminated with NCO, a cross-linking agent, an organic solvent and alithium salt.

[0014] The above and other objects of the present invention are furtherachieved by providing a method of preparing a cross-linked polyetherurethane polymeric electrolyte including mixing a pre-polymer having apolyethylene oxide backbone and terminated with NCO, with across-linking agent, an organic solvent and a lithium salt, andcross-linking the mixture.

[0015] The above and other objects of the present invention are stillfurther achieved by providing a lithium battery including a cathode, ananode and a cross-linked polyether urethane polymeric electrolyteinterposed between the cathode and the anode, and prepared by reacting apre-polymer having a polyethylene oxide backbone and terminated withNCO, a cross-linking agent, an organic solvent and a lithium salt.

[0016] A separator which has a network structure and is made of aninsulating resin, may be further provided between the cathode and theanode.

[0017] The above and other objects of the present invention are stillyet further achieved by providing a method of manufacturing a lithiumbattery including mixing a pre-polymer having a polyethylene oxidebackbone and terminated with NCO, with a cross-linking agent, an organicsolvent and a lithium salt, casting the mixture on at least one selectedsurface of the cathode and the anode, and cross-linking the resultantproduct.

[0018] Alternatively, the above and other objects of the presentinvention may be achieved by providing a method of manufacturing alithium battery including mixing a prepolymer having a polyethyleneoxide backbone and terminated with NCO, with a crosslinking agent, anorganic solvent and a lithium salt, interposing a separator between acathode and an anode to form an electrode assembly and accommodating theelectrode assembly into a battery case, and injecting the mixture intothe battery case and crosslinking the resultant product.

[0019] In the polymeric electrolyte and lithium battery, the pre-polymerused in the preparation of the cross-linked polyether urethane, isobtained by reacting isocyanate with glycol selected from polyethyleneglycol, polypropylene glycol and a combination thereof. Here, theisocyanate is preferably at least one selected from the group consistingof tolylene 2,4-diisocyanate, tolylene 2,6-diisocyanate, diphenylmethane4,4′-diisocyanate, hexamethylene diisocyanate, diphenylmethanediisocyanate, isophoprone diisocyanate, triphenylmethane diisocyanate,tris-(isocyanatephenyl) thiophosphate, lysine ester triisocyanate,1,8-diisocyanate-4-isocyanatemethylocartane, undecane1,6,11-triisocynate, hexamethylene 1,3,6-trisisocyanate andbicycloheptane triisocyanate.

[0020] The cross-linking agent used in the present invention ispreferably at least one selected from the group consisting of glycerolethoxylate, glycerol propoxylate, 3-methyl-1,3,5-pentanetriol andcaprolactone.

[0021] In the method of manufacturing the polymeric electrolyte andlithium battery, the temperature of cross-linkage is preferably in therange from 25 to 65° C.

[0022] In the polymeric electrolyte and lithium battery according to thepresent invention, the lithium salt is preferably at least one selectedfrom the group consisting of lithium perchlorate (LiClO₄), lithiumtetrafluoroborate (LiBF₄), lithium hexafluorophosphate (LiPF₆), lithiumtrifluoromethanesulfonate (LiCF₃SO₃) and lithiumbistrifluoromethanesulfonyl amide (LiN(CF₃SO₂)₂). Also, the organicsolvent is preferably at least one solvent selected from the groupconsisting of propylene carbonate, ethylene carbonate, dimethylcarbonate, methylethyl carbonate, diethyl carbonate and vinylenecarbonate.

[0023] In the lithium battery according to the present invention, theelectrode assembly is preferably a winding type and the battery case ispreferably a pouch.

[0024] In the lithium battery according to the present invention, theweight of a mixture of the organic solvent and lithium salt ispreferably 3 to 30 times that of the pre-polymer. In particular, in thecase where a separator is included in the electrode assembly, the weightof a mixture of the organic solvent and lithium salt is preferably 5 to30 times that of the prepolymer. Also, in the case where a separator isnot included in the electrode assembly, the weight of a mixture of theorganic solvent and lithium salt is preferably 3 to 15 times that of thepre-polymer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above objects and advantages of the present invention willbecome more apparent by describing in detail preferred embodimentsthereof with reference to the attached drawings in which:

[0026]FIG. 1 shows a linear sweeping voltammogram for measuring theelectrochemical stability of a polymeric electrolyte prepared accordingto the present invention, in which SR standing for scan rate means avoltage added rate;

[0027]FIG. 2 shows a standard charging/discharging curve of a lithiumsecondary battery containing the polymeric electrolyte preparedaccording to an embodiment of the present invention; and

[0028]FIG. 3 shows a rated charging/discharging curve of a lithiumsecondary battery containing the polymeric electrolyte preparedaccording to an embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Reference will now made in detail to the present preferredembodiments of the present invention, examples of which are illustratedin the accompanying drawings. The embodiments are described below inorder to explain the present invention by referring to the figures.

[0030] A feature of the present invention lies in the fact that across-linked polyether urethane polymeric electrolyte prepared byreacting a pre-polymer having a polyethylene oxide backbone andterminated with NCO, with a cross-linking agent, an organic solvent anda lithium salt, is used as a polymeric electrolyte. A polyether urethanepolymeric electrolyte prepared by adding the pre-polymer to a mixture ofa cross-linking agent, an organic solvent and a lithium salt, injectingthe same into a case accommodating an electrode assembly andcross-linking the resultant product, is preferred.

[0031] The pre-polymer is obtained by reacting isocyanate with glycolselected from the group consisting of polyethylene glycol, polypropyleneglycol and a combination thereof.

[0032] According to a known journal describing the measurement result ofthe electrochemical stability of a polyurethane-based compoundsynthesized to be used as an electrolyte of a lithium battery, thedissolution potential of a urethane-based electrolyte is approximately4.2 V (vs. lithium), which is difficult to be used in a lithiumsecondary battery (Journal of Power Sources 84(1999) pp.12-23). However,the present invention has been completed by improving theelectrochemical stability of a polyurethane electrolyte.

[0033] A method of preparing a cross-linked polyether urethane polymericelectrolyte according to the present invention will now be described.

[0034] A one-shot process and a pre-polymer process are generally usedin preparing a urethane bond. In the present invention, the urethanebond was formed by using the prepolymer process.

[0035] The process of preparing a polyether urethane polymericelectrolyte according to the present invention will now be described.First, a pre-polymer having a polyethylene oxide backbone andconstructed with NCO termination, is prepared by reacting a glycolselected from polyethylene glycol, polypropylene glycol and acombination thereof, with isocyanate.

[0036] The isocyanate is preferably at least one selected from the groupconsisting of tolylene 2,4-diisocyanate, tolylene 2,6-diisocyanate,diphenylmethane 4,4′-diisocyanate, hexamethylene diisocyanate,diphenylmethane diisocyanate, isophorone diisocyanate, triphenylmethanediisocyanate, tris-(isocyanatephenyl) thiophosphate, lysine estertriisocyanate, 1,8-diisocyanate-4-isocyanatemethyloctane, undecane1,6,11-triisocynate, hexamethylene 1,3,6-trisisocyanate andbicycloheptane triisocyanate.

[0037] Then, the pre-polymer is added to a mixture of a cross-linkingagent, an organic solvent and a lithium salt and reacted to prepare apolymeric electrolyte according to the present invention.

[0038] The cross-linking agent is preferably glycerol ethoxylate orglycerol propoxylate.

[0039] Also, the organic solvent and the lithium salt are not restrictedto a special organic solvent and lithium salt, but to any organicsolvent and lithium salt that are widely known in the art. Preferably,the lithium salt is at least one selected from the group consisting ofLiClO₄, LiBF₄, LiPF₆, LiCF₃SO₃, LiN(CF₃SO₂)₂. The organic solvent ispreferably at least one selected from the group consisting of propylenecarbonate, ethylene carbonate, dimethyl carbonate, methylethylcarbonate, diethel carbonate and vinylene carbonate. Also, the weight ofa mixture of the organic solvent and lithium salt is preferably 3 to 30times that of the pre-polymer. The concentration of the lithium salt inthe mixture is preferably 0.5 to 2 M.

[0040] In order to facilitate cross-linkage, it is preferred that acatalyst such as dibutyltin dilaurate is further added to a compositionfor the polymeric electrolyte. The temperature for cross-linkage ispreferably in the range from 25 to 65° C.

[0041] A method of preparing a lithium battery containing the polymericelectrolyte according to the present invention will now be described.

[0042] First, an electrode active material layer is formed on a currentcollector using an electrode active material composition comprising anelectrode active material, a binder, a conductive agent and a solvent.Here, the electrode active material layer may be formed such that theelectrode active material composition is directly coated on the currentcollector or the electrode active material composition is coated on aseparate support body and dried and then a film peeled off from thesupport body is laminated on the current collector. Here, as the supportbody, any material that can support the active material layer may beused, and detailed examples thereof include a mylar film and apolyethylene terephthalate (PET) film.

[0043] In the present invention, a lithium composite oxide such asLiCoO2 may be used as the electrode active material for a cathode andcarbon or graphite may be used as the electrode active material for ananode. As the conductive agent, carbon black or the like can be used.Here, the content of the conductive agent is preferably 1 to 20 parts byweight based on 100 parts by weight of the electrode active material,e.g., LiCoO₂.

[0044] As the binder, vinylidenefluoride-hexafluoropropylene (VdF/HFP)copolymer, polyvinylidenefluoride, polyacrylonitrile,polymethylmethacrylate and mixtures thereof may be used, and the contentthereof is preferably 5 to 30 parts by weight based on 100 parts byweight of the electrode active material.

[0045] All solvents for use in the conventional lithium battery can beused as the solvent, and detailed examples thereof include acetone andN-methylpyrrolidone.

[0046] In some cases, in order to improve the performance of a battery,Li₂CO₃ may be further added to the electrode active materialcomposition.

[0047] The separator of the present invention is not specificallylimited and usable separators include an easily windable polyethyleneseparator and polypropylenelpolyethylene/polypropylene three-layeredseparator. Also, since the polymeric electrolyte prepared according tothe present invention serves as a separator, it is not necessary to usea separate separator.

[0048] A separator is interposed between the cathode and anode platesprepared in the above-described manner, and wound by a jelly-roll methodto form an electrode assembly or a bi-cell electrode assembly.Subsequently, the electrode assembly is put into a case. Next, the thusformed pre-polymer having a polyethylene backbone and terminated withNCO is added to a mixture having a cross-linking agent, a lithium saltand an organic solvent, and then the resultant material is injected intothe case.

[0049] Thereafter, the case is hermetically sealed and then theresultant product is allowed to stand in an oven maintained at apredetermined temperature for a predetermined time. Here, the oven ispreferably maintained at a temperature in the range from 25 to 65° C. Ifthe temperature of the oven exceeds 65° C., the electrolytic solution isdecomposed to be undesirably discolored.

[0050] Then, as a result of the reaction, thermal polymerization occursto the pre-polymer to generate a cross-linked product, thereby gellingthe electrolytic solution. If the electrolytic solution exists in a geltype, it is unlikely to be leaked outside, thereby preventing loweringof the stability and reliability of the battery due to leak age ofelectrolytic solution.

[0051] Alternatively, in the case of not using a separate separator, thethus formed prepolymer having a polyethylene backbone and terminatedwith NCO is added to a mixture having a cross-linking agent, a lithiumsalt and an organic solvent, and then the resultant product is cast on acathode plate, an anode plate or both plates, and then thermallypolymerized in an oven, thereby fabricating the lithium batteryaccording to the present invention.

[0052] The lithium battery according to the present invention is notspecifically limited in terms of type, and includes both a lithiumprimary battery and a lithium secondary battery.

[0053] The present invention will now be described through the followingexamples and is not limited thereto.

EXAMPLE 1

[0054] 4 g of polyethyleneglycol having a molecular weight of 400 and4.205 g of hexamethylene diisocyanyate were reacted at 65° C. to preparea pre-polymer having a polyethyleneoxide backbone and terminated withNCO. Here, as a catalyst, 0.092 g (approximately 1 wt %) of dibutyltindilaurate was used.

[0055] Subsequently, 0.085 g of the pre-polymer was mixed with 0.077 gof glycerol ethoxylate as a cross-linking agent, 2.92 g of a mixedsolution containing 1.3 M LiPF₆ and ethylene carbonate/propylenecarbonate/diethyl carbonate in the mixture ratio of 41:49:10, and 0.0235g of dibutyl dilaurate. 3 g of the mixture was put into a pouch having awindable jelly roll, sealed, and then allowed to stand for 2 days. Then,the resultant product was thermally cross-linked at 65° C. for 4 hoursto prepare a polymeric electrolyte.

[0056] The standard charging/discharging data (0.5C charging, 0.2Cdischarging) of the lithium secondary battery (nominal capacity: 800mAh) prepared by employing the thus formed polymeric electrolyte, isshown in FIG. 2. In FIG. 2, (a) denotes a standard charging curve of alithium secondary battery and (b) denotes a standard charging curve of alithium battery.

EXAMPLE 2

[0057] A pre-polymer for forming polyether urethane polymer was preparedin the same manner as in Example 1.

[0058] Subsequently, 0.1 g of the pre-polymer was mixed with 0.091 g ofglycerol ethoxylate as a cross-linking agent and 2.28 g of a mixedsolution containing 1.3 M LiPF6 and ethylene carbonate/propylenecarbonate/diethyl carbonate in the mixture ratio of 41:49:10. Themixture was allowed to stand at 25° C. for 12 hours to prepare apolymeric electrolyte.

[0059] The polymeric electrolyte was interposed between an anode (Li)and a cathode (LiCoO₂) to prepare a coin cell. The charging/dischargingcharacteristics of the coin cell were measured by rate at 2.75 to 4.3 Vand the result is shown in FIG. 3. In FIG. 3, (a) denotes a ratedcharging curve of a lithium secondary battery and (b) denotes a rateddischarging curve of a lithium battery.

EXPERIMENTAL EXAMPLE 1

[0060] This experiment is to measure the electrochemical stability ofpolyether urethane polymeric electrolyte prepared in Examples 1 and 2.

[0061] The dissolution potential of the polyether urethane polymericelectrolyte prepared in Example 1 was measured using a lithium electrodeand a stainless (sus) electrode and the result is shown in FIG. 1.

[0062]FIG. 1 shows a linear sweeping voltammogram for measuring theelectrochemical stability of a polymeric electrolyte prepared accordingto the present invention. FIG. 1 showed that the polyether urethanepolymeric electrolyte according to the present invention waselectrochemically stable even at 5.0 V or higher.

[0063] Thus, the polymeric electrolyte according to the presentinvention is suitably used for a lithium secondary battery in which apolymeric electrolyte free of danger of being dissolved at 2.75 to 4.3 Vmust be used.

[0064] Since the lithium secondary battery according to the presentinvention employs an electrochemically stable polyether urethanepolymeric electrolyte, the reliability and safety of the lithiumsecondary battery can be improved.

[0065] Although the present invention has been described with referenceto the preferred examples, the foregoing disclosure should beinterpreted as illustrative only and it should be understood thatvarious modifications and variations can be easily made by those skilledin the art without departing from the spirit of the invention.Accordingly, a true scope and spirit of the invention should be definedby the following claims.

What is claimed is:
 1. A polymeric electrolyte comprising a cross-linkedpolyether urethane prepared by reacting a pre-polymer having apolyethylene oxide backbone and terminated with NCO, with across-linking agent, an organic solvent and a lithium salt.
 2. Thepolymeric electrolyte according to claim 1, wherein the pre-polymer isobtained by reacting isocyanate with a glycol selected from the groupconsisting of polyethylene glycol, polypropylene glycol and acombination thereof.
 3. The polymeric electrolyte according to claim 2,wherein the isocyanate is at least one selected from the groupconsisting of tolylene 2,4-diisocyanate, tolylene 2,6-diisocyanate,diphenylmethane 4,4′-diisocyanate, hexamethylene diisocyanate,diphenylmethane diisocyanate, isophoprone diisocyanate, triphenylmethanediisocyanate, tris-(isocyanatephenyl) thiophosphate, lysine estertriisocyanate, 1,8-diisocyanate-4-isocyanatemethylocartane, undecane1,6,11-triisocynate, hexamethylene 1,3,6-trisisocyanate andbicycloheptane triisocyanate.
 4. The polymeric electrolyte according toclaim 1, wherein the cross-linking agent is at least one selected fromthe group consisting of glycerol ethoxylate, glycerol propoxylate,3-methyl-1,3,5-pentanetriol and caprolactone.
 5. The polymericelectrolyte according to claim 1, wherein the lithium salt is at leastone selected from the group consisting of lithium perchlorate (LiCIO₄),lithium tetrafluoroborate (LiBF₄), lithium hexafluorophosphate (LiPF₆),lithium trifluoromethanesulfonate (LiCF₃SO₃) and lithiumbistrifluoromethanesulfonyl amide (LiN(CF₃SO₂)₂).
 6. The polymericelectrolyte according to claim 1, wherein the organic solvent is atleast one solvent selected from the group consisting of propylenecarbonate, ethylene carbonate, dimethyl carbonate, methylethylcarbonate, diethyl carbonate and vinylene carbonate.
 7. The polymericelectrolyte according to claim 1, wherein a total weight of the organicsolvent and the lithium salt is 3 to 30 times that of the pre-polymer.8. The polymeric electrolyte according to claim 7, wherein aconcentration of the lithium salt in the cross-linked polyether urethaneis 0.5 to 2M.
 9. A method of preparing a cross-linked polyetherpolymeric electrolyte comprising: mixing a pre-polymer having apolyethylene oxide backbone and terminated with NCO, with across-linking agent, an organic solvent and a lithium salt, to obtain amixture and cross-linking the mixture.
 10. The method according to claim9, wherein the cross-linking comprises heating the mixture at atemperature in a range from 25 to 65° C.
 11. A lithium batterycomprising: a cathode; an anode; and a cross-linked polyether urethanepolymeric electrolyte interposed between the cathode and the anode, andprepared by reacting a pre-polymer having a polyethylene oxide backboneand terminated with NCO, a cross-linking agent, an organic solvent and alithium salt.
 12. The lithium battery according to claim 11, wherein thecross-linking agent is at least one selected from the group consistingof glycerol ethoxylate, glycerol propoxylate,3-methyl-1,3,5-pentanetriol and caprolactone.
 13. The lithium batteryaccording to claim 11, wherein the isocyanate is at least one selectedfrom the group consisting of tolylene 2,4-diisocyanate, tolylene2,6-diisocyanate, diphenylmethane 4,4′-diisocyanate, hexamethylenediisocyanate, diphenylmethane diisocyanate, isophoprone diisocyanate,triphenylmethane diisocyanate, tris-(isocyanatephenyl) thiophosphate,lysine ester triisocyanate, 1,8-diisocyanate-4-isocyanatemethylocartane,undecane 1,6,11-triisocynate, hexamethylene 1,3,6-trisisocyanate andbicycloheptane triisocyanate.
 14. The lithium battery according to claim11, wherein the lithium salt is at least one selected from the groupconsisting of lithium perchlorate (LiClO₄), lithium tetrafluoroborate(LiBF₄), lithium hexafluorophosphate (LiPF₆), lithiumtrifluoromethanesulfonate (LiCF₃SO₃) and lithiumbistrifluoromethanesulfonyl amide (LiN(CF₃SO₂)₂).
 15. The lithiumbattery according to claim 11, wherein the organic solvent is at leastone solvent selected from the group consisting of propylene carbonate,ethylene carbonate, dimethyl carbonate, methylethyl carbonate, diethylcarbonate and vinylene carbonate.
 16. The lithium battery according toclaim 11, wherein the total weight of the organic solvent and lithiumsalt is 3 to 30 times that of the pre-polymer.
 17. The lithium batteryaccording to claim 16, wherein a concentration of the lithium salt inthe cross-linked polyether urethane is 0.5 to 2M.
 18. The lithiumbattery according to claim 11, further comprising a separator having anetwork structure and made of an insulating resin, between the cathodeand the anode.
 19. The lithium battery according to claim 11, whereinthe separator is formed of one selected from the group consisting ofpolypropylene, polyethylene and a combination thereof.
 20. A method ofmanufacturing a lithium battery comprising: mixing a pre-polymer havinga polyethylene oxide backbone and terminated with NCO, with across-linking agent, an organic solvent and a lithium salt, to obtain amixture; casting the mixture on a surface of at least one of a cathodeand an anode so as to be between the cathode and the anode; andcross-linking the resultant product.
 21. The method according to claim20, wherein the cross-linking comprises heating the resultant product ata temperature in a range from 25 to 65° C.
 22. A method of manufacturinga lithium battery comprising: mixing a pre-polymer having a polyethyleneoxide backbone and terminated with NCO, with a cross-linking agent, anorganic solvent and a lithium salt, to obtain a mixture; interposing aseparator between a cathode and an anode to form an electrode assemblyand accommodating the electrode assembly into a battery case; andinjecting the mixture into the battery case having the electrodeassembly and crosslinking the resultant product.
 23. The methodaccording to claim 22, wherein the separator is formed of one selectedfrom the group consisting of polypropylene, polyethylene and acombination thereof.
 24. The method according to claim 22, wherein thecross-linking comprises heating the resultant product at a temperaturein a range from 25 to 65° C.
 25. The lithium battery according to claim11, wherein the cathode or the anode comprises: a current collector; anelectrode active material layer formed on the current collector, theelectrode active material layer comprising: an electrode activematerial, a binder, a conductive agent, and a solvent.
 26. The methodaccording to claim 20, further comprising: forming an electrode activematerial layer by adding an electrode active material, a binder, aconductive agent, and a solvent; and coating the electrode activematerial layer on a current collector, to obtain the cathode or theanode.
 27. The method according to claim 20, further comprising: formingan electrode active material layer by adding an electrode activematerial, a binder, a conductive agent, and a solvent; coating theelectrode active material layer on a support body; peeling the electrodeactive material from the support body; and laminating the peeledelectrode active material on a current collector, to obtain the cathodeor the anode.
 28. The method according to claim 22, further comprising:forming an electrode active material layer by adding an electrode activematerial, a binder, a conductive agent, and a solvent, and coating theelectrode active material layer on a current collector, to obtain thecathode or the anode.
 29. The method according to claim 22, furthercomprising: forming an electrode active material layer by adding anelectrode active material, a binder, a conductive agent, and a solvent;coating the electrode active material layer on a support body; peelingthe electrode active material from the support body; and laminating thepeeled electrode active material on a current collector, to obtain thecathode or the anode.
 30. A method of manufacturing a lithium batterycomprising: mixing a pre-polymer having a polyethylene oxide backboneand terminated with NCO, with a cross-linking agent, an organic solventand a lithium salt, to obtain a mixture; forming an electrode assemblywith the cathode and the anode, and accommodating the electrode assemblyinto a battery case; and injecting the mixture into the battery casehaving the electrode assembly and crosslinking the resultant product.